Power conversion burner head



Dec. 30, 1969 H. H. GROBE POWER CONVERSION BURNER HEAD 2 Sheets-Sheet 1 Filed April 16, 1968 Dec. 30, 1969 H. H. GROBE POWER CONVERSION BURNER HEAD 2 Sheets-Sheet 2 Filed April 16, 1968 Q AVE United States Patent O 3,486,835 POWER CONVERSION BURNER HEAD Henry H. Grobe, Jamaica, N.Y., assignor to Sun-Ray Burner Manufacturing Corp., Jamaica, N.Y., a corporation of New York Filed Apr. 16, 1968, Ser. No. 721,679 Int. Cl. F23n 5/08, 1 /00 US. Cl. 43179 8 Claims ABSTRACT OF THE DISCLOSURE A power conversion burner head for burning a fuel and air mixture at its outlet end including flame quality control means comprising detector means responsive to the light energy of the flame of combustion and deactivating means operatively connected to the detector means and adapted to shut off the flow of fuel to the burner head when the light energy of said flame falls below a predetermined value. The burner head includes inner, middle and outer conduits defining a central air passage, a fuel passage and an outer air passage respectively. Disposed within the outer conduit adjacent the burner head outlet end is a frustoconical combustion retainer having vanes struck inwardly therefrom and defining slots therein of corresponding dimensions.

BACKGROUND OF THE INVENTION This invention relates generally to burners disposed at the entrance Opening of combustion chambers and furnaces and utilized for the mixture and combustion of fuels and air. Such burners must completely mix the fuel, which may be gaseous such as natural gas, a pulverized solid such as coal, or an atomized liquid such as oil, with the air in controlled proportions for the purpose of ignition and combustion. If the fuel and air are not properly mixed or if the proportions thereof are improper, uniform combustion will not be sustained in the burner or large amounts of undesirable, if not dangerous,'products of the combustion process will be emitted into the combustion chamber. These products include carbon monoxide and carbon black and their emission from furnaces is a substantial cause of air pollution. Of course, the presence of excessive amounts of carbon monoxide creates a more immediate danger to health in view of the likelihood of its escape into an occupied room.

If combustion is not uniformly sustainedfor if undesirable amounts of pollutants are being emitted, the burner must be shut down as a safety measu'leand the cause of the condition must be identified and corrected.

The known power conversion burner heads are generally provided with thermocouple or other means for detecting the extinguishing of the flame of combustion or the failure of ignition thereof, but are not provided with automatic means for detecting'the quality of said flame.

SUMMARY OF INVENTION Generally speaking, in accordance with the invention, a power conversion burner head is provided including flame quality control means comprising detector means responsive to the light energy of the flame and deac- "ice radially spaced from the middle conduit defining therebetween an outer air passage. Means is provided for mixing the fuel from the fuel passage with the air flowing through the central air passage before combustion. A combustion retainer is disposed within the outer conduit at the end of the central air and fuel passages. The combustion retainer is frustoconical and has vanes struck inwardly therefrom and defining slots therein of corresponding dimensions. A pair of ignition electrodes are disposed with their respective outer ends in spaced relation adjacent the front end of the combustion retainer, said electrodes being adapted to ignitethe fuel-air mixture.

Accordingly, it is an object of this invention to provide a power conversion burner head adapted to preclude the excessive emission of undesirable combustion by-products. I

Another object of the invention is to provide a power conversion burner head which will automatically shut off the flow of fuel if combustion is not properly sustained.

A further object of the invention is to provide a power conversion burner which completely mixes the fuel and air and which retains the flame of combustion within the burner.

Still another object of the invention is to provide a power conversion burner including photo-sensitive means for detecting the quality of the flame of combustion.

Another object of the invention is to provide a power conversion burner head adapted to burn fuels and particularly adapted to burn and monitor the combustion of gaseous fuels such as natural gas.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises the features of construction, combination of elements, and arrangements of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of the power conversion burner head in accordance with the invention;

FIG. 2 is a partial sectional view taken along th plane 2-2 of FIG. 1;

FIG. 3 is a partial sectional view taken along the lines 33 of FIG. 2;

' FIG. 4 is a fragmentary sectional view taken along the lines 4-4 of FIG. 3; and

' FIG. 5 is a schematic view of the flame qualitycontrol means of the power conversion burner head according to the invention.

- DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 through 4, the power conversion burner head 10 depicted includes an inner conduit 12, a middle conduit 14, and outer conduit 16. The three conduits 12, 14 and 16 are substantially cylindrical and concentric.

Inner conduit 12 defines a central air passage 18, air flowing therein in the direction of arrows 20. Inner conduit 12 and middle conduit 14 define therebetween fuel passage 22 wherein fuel flows in the direction of arrows 24. Fuel passage 22 is further defined by annular Wall 26 extending between the inner and middle conduits 12 and 14, fuel being delivered to passage 24 through aperture 28 which is connected to fuel delivery pipe 30 by connector 32. Connector 32 extends through and 3 provides a gas-tight fit with outer conduit 16. Disposed within connector 32 is orifice 34, the rate of flow of the fuel being determined by the diameter of the aperture 36 in said orifice.

Middle and outer conduits 14 and 16 define therebetween outer air passage 38 wherein air flows in the direction of arrows 40. Frictionally engaged with outer' conduits 16 at its outlet end 42 is a funnel member 44 adapted to direct the flow of the products of combustion and defining the outlet end of the power conversion burner head. Frictionally engaged about the outlet end of middle conduit 14 is cap 46 which consists of a transverse wall 48 having a central aperture 50 formed therein and a longitudinally extending wall 52 in frictional engagement with middle conduit 14. As shown in FIGS. 2 and 4, middle conduit 14 extends beyond inner conduit 12 in the direction of the outlet end of power conversion burner head 10. Accordingly, transverse wall 48 tends to direct the fuel flowing in fuel passage 22 inwardly so that it mixes with the air flowing in central air passage 18. In effect, an annular column of fuel is directed inwardly on the cylindrical column of air from central air passage 18, causing the thorough mixing of said fuel and air which then passes through aperture 50. The diameter of aperture 50 is preferably equal to the diameter of inner conduit 12 so that all of the fuel is directed into the air, while a maximum passage is provided for the flow of the air-fuel mixture in the direction of arrow 54.

Secured to longitudinally extending wall 52 of cup 46 are L-shaped support members 56. The radially extending leg of L-shaped support members 56 serve as spacers to maintain and support middle conduit 14 in spaced concentric relation with outer conduit 16. Spacers 58 are provided between inner conduit 12 and middle conduit 14 to maintain these conduits in spaced concentric relation.

As can be seen from the drawings, outlet end 42 of conduit 16 extends beyond the outlet end of middle conduit 14. Disposed within outer conduit 16 between outlet end 42 and cap transverse wall 48 is combustion retainer 60, secured to the longitudinally extending leg of L- shaped support members 56. Combustion retainer 60 is frustoconical, its axis being aligned with the axis of the three concentric conduits 12, 14 and 16. The rear circular end edge 62 of said combustion retainer is of smaller diameter than front circular end edge 64 and is proximate to and of substantially equal diameter to aperture 50 in transverse wall 48. The latter arrangement permits the unobstructed flow of the air-fuel mixture into the combustion retainer. Front end edge 64 extends radially beyond middle conduit 14 and is radially spaced from outer conduit 16.

Struck inwardlyfrom combustion retainer 60 are vanes '66 defining slots 68 therein of corresponding dimensions. Vanes 66 are laterally aligned and equally spaced circumferentially. They are inclined at an acute angle to the combustion retainer 60 so as to partially overlie slots 68.

Combustion retainer 60 is adapted to further insure proper mixing of the air and gas and to retain the flame of combustion substantially within the confines of said combustion chamber. The latter purpose is important since the location of the flame of combustion contributes to the proper operation of the flame quality control means to be discussed below and since, in that location, the flame is shielded by combustion retainer and outer conduit 16 so that it will not be extinguished by stray drafts in the furnace itself.

At least a portion of the air flowing through outer air passage 38 passes through slots '68 and is deflected by vanes 66 to form a circumferential stream of air about the inside of combustion retainer 60. A dead air space or partial vacuum is formed between the cylindrical stream of fuel and air flowing through aperture 50 and combustion retainer rear end 62 and the circumferentially flowing stream of air adjacent the inner surface of combustion retainer 60. This partial vacuum tends to draw the air-gas mixture radially outwardly from the main longitudinal stream. As a result, the flame of combustion is confined within said combustion retainer and is not blown out forwardly thereof. Any excess air from outer air passage 40 passes out of the out end of power conversion burner head 10 with the products of combustion.

Centrally disposed within central air passage 18 and spaced from inner conduit 12 is detector means 70 which is responsive to the light energy of the flame of combustion. Detector means 70 is preferably formed from a semiconductor photodiode or scanner especially encapsulated so as not to be damaged by the heat generated by the combustion of the fuel-air mixture. The operative face 72 of the photodiode is disposed opposite and spaced from the flame of combustion. The operation of a semiconductor photodiode or a scanner is well known and will not be discussed herein. In effect, the current which can flow through the photodiode or scanner increases in proportion to the light energy applied thereto.

Detector means 70 is plugged into socket 74 which is secured by means of bracket 76 and rivet 78 to support 80. The portion of support 8'0 in the vicinity of bracket 78 is V-shaped to provide a three point frictional engagement with inner conduit 12. The other end of support 80 is provided with tabs 81 adapted to limit the entry of the support into central air passage 18, thereby insuring the precise spacing between the operative face 72 of detector means 70 and the flame of combustion.

Leads 82 extend from socket 74 to connect detector means 70 with deactivating means 84 shown schematically in FIG. 5. When flame 86 is extinguished, sputters, or emits less than a predetermined amount of light energy due to insuflicient fuel or air, detector means 70 actuates deactivating means 84 to cut off the flow of fuel to the power conversion burner head at fuel pipe 30. Deactivating means 84 can be any of the known types of electrically actuated valves. One preferred arrangement is to have the reduced flow of current in a semiconductor photodiode in response to a decrease in the light energy imparted thereon cause a relay to operate which in turn actuates a valve to cut off the flow of fuel. Further, leads 88 may be connected to further circuitry adapted to actuate an audible or visible alarm or to deactivate a fan or the like providing air to the burner head, thereby shutting down the entire power conversion burner.

It has been found that the light energy output of the central core of the flame of combustion varies in relation to the proportion of fuel and air being burned. The light energy output of the flame of combustion reaches a peak in the range wherein the fuel and air are optimumly proportioned. This optimum combustion condition occurs when a minimum amount of pollulants such as carbon black and carbon monoxide are included in the products of combustion. When the proportions of fuel and air are such that combustion will be maintained but excessive quantities of carbon black and/or carbon monoxide are produced, it has been found that the light energy emitted by the flame of combustion is markedly reduced. If this undesirable, if not dangerous condition exists in a power conversion burner according to the invention, it will bedetected by detector means 70 which will actuate deactivating means 84 to shut off the flow of fuel to the burner head. The fuel-air mixture can then be adjusted, thereby avoiding substantial air pollution and the danger of carbon monoxide poisoning. It has been found that the power conversion burner head according to the invention is particularly effective where the fuel is a gas such as natural gas.

Any suitable ignition means, preferably electrical in nature may be provided. The embodiment shown in the drawings incorporates a pair of longitudinally extending ignition electrodes comprising high tension rods 90 sur rounded by and extending from high tension insulators 92. High tension rods 90 are bent inwardly toward the axis of burner headv and towardeach other to define a spark gap at outer ends 94 thereof. The spark gap, is disposed in the fuel-air stream adjacent the front end; of combustion retainer 60. Theignition electrodes are sup: ported-by base 96-which is secured tomiddle conduit; 14. The ignition electrodes mayrbe provided witha suitable highvoltagein the usual manner .by connecting a voltage source to terminals 97. After ignition, the flame of combustion is carried almost instantlyinto combustion retainer 60, whereit is maintained, as-stated. above in detail, by reason of the particular air flow pattern which is setup. 'Accordingly, once combustion is initiated, the ignition-means may be rendered inactive, by any suitable means, whether auto'rnaticor manual." Both said voltage source and said inactivation means are conventional and not shown.

The power conversion burner head according to the invention is preferably disposed in the wall of a combustion chamber or furnace so that only funnel member 44 extends within said combustion chamber or furnace. The inlet end of power conversion burner head 10. as defined by flange 98 of outer conduit 16 is preferably secured to a housing which contains means for providing air under pressure to central and outer air passages 18 and 38. The housing, which is not shown, may also contain the voltage source and inactivation means for the ignition electrodes, deactivating means 84, and such other safety and control devices as may be required to operate a power conversion burner and furnace.

The power conversion burner head according to the invention offers several substantial advantages over the known burner heads. The structure of the burner head is particularly adapted for the eflicient mixing of air and fuel before combustion. Further, the central air delivery passage 18, permits the disposition of detector means 70 within the power conversion burner head and spaced from the flame of combustion so that said detector means may detect variations in the light energy of the core of the flame of combustion. As pointed out above, this disposition permits the detection of not only ignition failure and the extinguishing of the flame but also the production of excessive pollutants, as indicated by the reduced light energy of said flame. In this connection, combustion retainer 60 serves to retain the flame of combustion within its confines to maintain the spacing between the flame of combustion and the detector means operative face 72 so as to permit accurate calibration of deactivating means 8'4. The above mentioned spacing also serves to prevent damage to detector means 70 such as light as might be caused by the extremely high temperatures present in the region immediately adjacent to the flame. Finally, the power conversion head according to the invention may be utilized with a variety of fuels including atomized oil, gases such as natural gas and pulverized solids such as coal.

It will thus be seen that the objects set forth above, and those made apparent from the preceding description are efficiently attained and, 'since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interposed as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. A power conversion burner head for burning a fuel and air mixture at its outlet end, including flame quality control means comprising detector means responsive to the light energy of the flame of combustion of said fuel and air, said detector means being disposed within said burner head so as to face and be spaced from said burner head outlet end; and deactivating means operatively connected to said detector means and adapted to shut off the flow of said fuel to said burner head when the light energy. of said flame falls belowa predeterminedvalue said burner head including a longitudinally extending innerconduit defining a central air passage; a longitudinally extending middle conduit surrounding and radially spaced from said inner conduit and defining therebetween a fuel passage; and a longitudinally extending outer conduit surrounding and radially spaced from said middle conduit and defining therebetween an outer air passage, said central and outer air passages and said fuel passage terminating proximate said burner head outlet end, said detector means being disposed within said central air passage said middle conduit extending longitudinally beyond said inner conduit in the direction of said burner head outlet end, said burner head including a transverse wall extending across the end of said middle conduit proximate said burner head output, said transverse wall having a central aperture therein, whereby said fuel flowing through said fuel passage is directed toward and mixes with said air flowing through said central air passage, the resulting fuel and air mixture passing through said transverse wall central aperture.

2. A power conversion burner head as recited in claim 1, wherein said outer conduit extends longitudinally beyond said middle conduit in the direction of said burner head outlet end, said burner head including a combustion retainer disposed within said outer conduit, between said transverse wall and said burner head output end, said combustion retainer being frustoconical with its rear end being adjacent said transverse wall central aperture and of smaller diameter than its front end, said combustion retainer having vanes struck inwardly therefrom defining slots in said combustion retainer of corresponding dimensions, at least a portion of said air flowing through said outer air passage flowing through said combustion retainer slots to facilitate mixing of said air-fuel mixture and to substantially retain combustion within the confines of said combustion retainer.

3. A power conversion burner head as recited in claim 2, wherein said combustion retainer rear end is of substantially the same size as said transverse wall central aperture, said combustion retainer front end being dimensioned to extend radially beyond said middle conduit.

4. A power conversion burner head as recited in claim 3, wherein said inner, middle and outer conduits are substantially concentric cylinders.

5. A power conversion burner head as recited in claim 4, wherein said middle conduit is formed with an opening therein proximate the other end thereof, said burner head including an annular wall extending between said inner and middle conduits at said other end of said I middle conduit, and fuel delivery means connected to said aperture in said middle conduit.

6. A power conversion burner head for burning a fuel and air mixture at its outlet end comprising a longitudinally extending inner conduit defining a central air passage; a longitudinally extending middle conduit surrounding and radially spaced from said inner conduit and extending longitudinally beyond said inner conduit in the direction of said burner head outlet end, said inner and middle conduits defining therebetween a fuel passage; a longitudinally extending outer conduit surrounding and radially spaced from said middle conuit and defining therebetween an outer air passage; an a transverse wall extending across the end of said middle conduit proximate said burner head output, said transverse wall having a central aperture therein, said fuel passage terminating in said central air delivery passage, said outer and central air passages terminating proximate said burner head outlet end, whereby said fuel flowing through said fuel passage is directed toward and mixes with said air flowing through said central air passage, the resulting fuel and air mixture passing through said transverse wall central aperture said outer conduit extending longitudinally beyond said middle conduit in the direction of said burner head outlet end, said burner head including a combustion retainer disposed within said outer conduit between said transverse wall and said burner head outlet end, said combustion retainer being frustoconical, having a read end adjacent said transverse wall central aperture and of smallerdiameter than its front end, said combustion retainer having vanes struck inwardly therefrom defining slots in said combustion retainer of corresponding dimen sions, at least a portion of said air flowing through said outer air passage flowing through said combustion retainer slots to facilitate the mixing of said air-fuel mixture and to substantially retain combustion within the confines of said combustion retainer.

7. A power conversion burner head as recited in claim 6, wherein said inner, middle and outer conduits are substantially concentric cylinders, said combustion retainer 8v frontend' being dimension said middle conduit 1 8. A power conversion burner head as recited in" claim 6, including a pair of ignition electrodes disposed within said outer air passage and having their respective outer ends in spaced relation to define a spark gap, said spark gap behind disposed adjacent said combustionretainer front end.

1 J References Cited j UNITED STATES PATENTS 1,646,456

to extend radially beyond 10/1927- Noreen et al. 23 9- 416. 4 3,299,841 1/1967 -H emker et al. 431 79X 3,304,989

2/1967 Alexander et a1. 4317.9 X

EDWARD G. FAVORS, Primary Examiner 

